The present invention relates generally to multimedia networks, and more particularly, to a method and system for distributed queues in a multimedia network with proxies.
With advancements in digital bus technologies, a variety of consumer electronic and computing devices can be integrated to form a multimedia network, for example, an audio/video (AV) network. One such bus standard is the Institute of Electrical and Electronics Engineers 1394 (IEEE 1394) digital interface standard, which enables high speed data communication between consumer electronic devices such as, video camcorders, electronic still cameras, computers, and digital audio and video equipment.
Furthermore, higher layer communication protocols, such as International Electrotechnical Commission 61883 (IEC 61883), Audio Video Control (AV/C), and Home Audio/Video interoperability (HAVi),standards, allow complex communication between consumer electronic devices. By taking advantage of these higher layer protocols and the IEEE 1394 bus standard, consumer electronic devices are becoming more integrated.
As these devices become integrated and perform more complex tasks, sharing of data between the devices becomes more important. Some devices in an AV network may perform data xe2x80x9ccapturingxe2x80x9d services, such as capturing digital still images, while other devices may perform specialized data xe2x80x9cprocessingxe2x80x9d services, such as printing or displaying the captured images. To integrate the data capturing with the data processing services, however, the devices in the AV network must somehow share the captured data.
As an illustration, consider an AV network that includes an IEEE 1394 bus connecting a plurality of video cameras to a printer. Each video camera in the AV network performs a data capturing service when. the video camera captures digital still images. The printer, on the other hand, performs a data processing service when the printer prints the captured images. To print the captured images, each video camera sends to the printer one or more requests, which may include one or more associated images. Since each request may include several associated images, and the printer may receive concurrent requests from a number of video cameras, the printer must have sufficient storage or memory resources to receive and store the requests and their associated images.
Most consumer electronic devices, however, have insufficient storage or memory resources to process such requests from a plurality of devices in an AV network because of the significant amount of data associated with the requests. To address the problem of limited storage and memory resources, U.S. application Ser. No. 09/239,696, filed Jan. 29, 1999, entitled xe2x80x9cMethod And System For Distributed Queues In A Multimedia Network,xe2x80x9d and filed concurrently herewith, described methods and systems for performing services in a multimedia network. These methods and systems queue in servicing devices a plurality of requests without the associated data and retrieve the associated data from one or more requesting devices only when a servicing device is ready to perform a service associated with a queued request.
These methods and systems, however, cannot establish requests for services while one or more servicing devices in the AV network are off-line. A servicing device may go off-line, for example, when a user temporarily removes or disconnects the servicing device from the AV network or when the user presses a pause button on the servicing device to temporarily halt processing in the servicing device. While the servicing device is off-line, requesting devices and other devices in the AV network must continue to store their requests and the associated data until the servicing device goes on-line again.
Furthermore, when a servicing device queues a request from a requesting device, the requesting device and other devices that provide the associated data must remain on-line until the servicing device serves the queued request. Moreover, since the servicing device retrieves the associated data from these devices only when the servicing device is ready to serve the queued request, depending on the number of queued requests, these devices may store the associated data for a significant period of time, and thus during that period, cannot use their limited memory and storage resources for performing other tasks. Finally, a user may wish to remove or disconnect a requesting device from the AV network after the requesting device sends a request to a servicing device but before the servicing device retrieves the associated data from the requesting device.
Therefore, it is desirable to have a method and system for performing services in a multimedia network with proxies that overcome the above and other disadvantages of the prior art.
Methods and systems consistent with the present invention perform services in a multimedia network, for example an audio/video (AV) network, by storing in a proxy device a plurality of requests for performing the services when one or more devices in the AV network are off-line. The proxy device may then retrieve the data associated with the stored requests from one or more devices in the AV network that provide the associated data. The associated data may include any type of digitized information, for example, text, audio, video, and graphics.
A service is broadly defined herein to include any processing performed by a servicing device using the associated data, for example, printing the associated data, displaying the associated data on a digital monitor, adding sound effects to the associated data, or adding visual effects or animation to the associated data, etc.
In accordance with an embodiment of the invention, the proxy device receives via a serial interface from requesting devices in the AV network a plurality of requests for performing services, for example printing digitally captured images, and stores the requests. When the requesting devices or other devices (hereinafter referred to as xe2x80x9cdata providing devicesxe2x80x9d) that provide the data associated with the stored requests are on-line, the proxy device retrieves the associated data from these devices and stores the associated data. Alternatively, the proxy device may not retrieve the associated data from the requesting devices or the data providing devices until one or more servicing devices request the associated data and the proxy device detects that the requesting devices and the data providing devices are on-line.
When the proxy device detects that one or more servicing devices in the AV network are on-line, the proxy device transfers the stored requests and the associated data to the servicing devices. The servicing devices then perform the services associated with the requests, for example, print the captured images, and return one or more results associated with the services to the proxy device. When the proxy device detects that the requesting devices or other devices that must receive the results are on-line, the proxy device sends the results to those devices.
The proxy device may include any computing device that includes a serial interface, which complies with a serial interface standard for networking consumer electronic devices, for example, IEEE 1394 standard. The requesting and servicing devices may include any consumer electronics or computing devices, for example digital video cameras, personal computers (PCs), digital video monitors, audio actuators, and video actuators that include a serial interface, which complies with a serial interface standard for networking consumer electronic devices, for example, IEEE 1394 standard.
Methods and systems consistent with the present invention have several advantages over the prior art. First, requesting devices in a multimedia network can transparently offload requests and the associated data to a proxy device when a servicing device is off-line, thereby allowing the requesting devices to perform other tasks. Second, requesting devices can establish a number of requests without requiring expensive memory and storage resources. Third, requesting devices and other devices that store the data associated with requests can temporarily go off-line without disrupting the ability of servicing devices to perform the associated services. Fourth, requesting devices and other devices that store the associated data do not have to store the data for a significant period of time, thereby making their limited storage and memory resources available for other tasks. Finally, users can remove or disconnect from the AV network a requesting device and other devices that store the associated data after the requesting device sends a request to a servicing device but before the servicing device retrieves the associated data from the proxy device.
The description of the invention and the following description for carrying out the best mode of the invention should not restrict the scope of the claimed invention. Both provide examples and explanations to enable others to practice the invention. The accompanying drawings, which form part of the description for carrying out the best mode of the invention, show several embodiments of the invention, and together with the description, explain the principles of the invention.